Animal models are being used throughout The Scripps Research Institute-Alcohol Research Center (TSRI-ARC) and Center at Large to pursue then neurobiological basis of ethanol intoxication, dependence, and vulnerability to relapse. Work in the Animal Model Development Unit of the Alcohol Research Center grant during the previous funding period has provided the foundation for the animal models that are being used throughout the Center. In the present proposal, the former Animal Model Development Unit has been assimilated into a Core component of the TSRI-ARC and the Center at Large. This is necessitated by the major advances in development of animal models during the previous funding period and the reliance of the animal components of the Center and the Center at Large on this facility. The Animal Model Core will serve 3 purposes for the proposed TSRI-ARC and Center at Large: 1) The Animal Model Core will provide the facilities for inducing dependence using the ethanol vapor chambers for all investigators in the TSRI-ARC and Center at Large, 2)The Animal Model Core will provide blood ethanol levels and vaginal smear data for TSRI-ARC and Center at Large, 3) The Animal Model Core will continue to refine the animal models of dependence to be utilized by the Center including exploring different lengths and amounts of ethanol exposure as well as the influence of gender and genetic variables. The Specific Aims of the Animal model development program are to: 1). Examine intermittent versus continuous ethanol vapor exposure models as a means to optimize allostatic processes, 2). Characterize ethanol self-administration in dependent female rats with respect to estrous cycle phase, 3). Examine genetic susceptibility to ethanol self-administration in dependent rats selectively bred for differential ethanol drinking, and 4). Examine genetic susceptibility to ethanol self-administration in dependent rats selectively bred for traits postulated to involve allostatic mechanisms. The service and animal model development proposed for this Core are a critical integrative part of the TSRI-ARC and Center at Large that provide a major contribution to the "centerness" of the program by standardization of animal models, collaborative interactions and communication among investigators.